code: def main():
      parser = get_parser()
      args = parser.parse_args()
  
      os.makedirs(args.save_dir, exist_ok=True)
  
      def create_files(dest):
          copyfile(
              osp.join(args.data, args.split) + ".tsv", dest + ".tsv"
          )
          if osp.exists(osp.join(args.data, args.split) + ".wrd"):
              copyfile(
                  osp.join(args.data, args.split) + ".wrd",
                  dest + ".wrd",
              )
          if osp.exists(osp.join(args.data, args.split) + ".phn"):
              copyfile(
                  osp.join(args.data, args.split) + ".phn",
                  dest + ".phn",
              )
  
          if osp.exists(dest + ".npy"):
              os.remove(dest + ".npy")
          npaa = NpyAppendArray(dest + ".npy")
          return npaa
  
      save_path = osp.join(args.save_dir, args.split)
      npaa = create_files(save_path)
  
      generator, num = get_iterator(args)
      iterator = generator()
  
      with open(save_path + ".lengths", "w") as l_f:
          for w2v_feats in tqdm.tqdm(iterator, total=num):
              print(len(w2v_feats), file=l_f)
  
              if len(w2v_feats) > 0:
                  npaa.append(w2v_feats.numpy())
  
file_path: fairseq/examples/wav2vec/unsupervised/scripts/wav2vec_extract_features.py
imports: import argparse
  import os
  import os.path
  import tqdm
  import torch
  import torch.nn.functional
  from shutil import copyfile
  from npy_append_array import NpyAppendArray
  import fairseq
  import soundfile
label_desc: Use image node_id 3 for calling a global function with example usage: main() and returns: npaa